I just tried it, yeah it does indeed work.
Maybe what’s failing for the OP is the boolean, the node seems set up correctly otherwise.
I think the approach I described is a bit better though in general since it gives you more control, you can share the same user variable name between many niagara systems and make each one react differently when it is set, but if you use the emitter enable node, you’d have to either name all emitters that need to be toggleable by it the same exact thing, or set the name in an instance editable variable which you change based on the system you’re using.